Adult exposure to insecticides causes persistent behavioral and neurochemical alterations in zebrafish

Publication date: Available online 3 January 2020Source: Neurotoxicology and TeratologyAuthor(s): Andrew B. Hawkey, Lilah Glazer, Cassandra Dean, Corinne N. Wells, Kathryn-Ann Odamah, Theodore A. Slotkin, Frederic J. Seidler, Edward D. LevinAbstractFarmers are often chronically exposed to insecticides, which may present health risks including increased risk of neurobehavioral impairment during adulthood and across aging. Experimental animal studies complement epidemiological studies to help determine the cause-and-effect relationship between chronic adult insecticide exposure and behavioral dysfunction. With the zebrafish model, we examined short and long-term neurobehavioral effects of exposure to either an organochlorine insecticide, dichlorodiphenyltrichloroethane (DDT) or an organophosphate insecticide chlorpyrifos (CPF). Adult fish were exposed continuously for either two or 5 weeks (10–30 nM DDT, 0.3–3 μM CPF), with short- and long-term effects assessed at 1-week post-exposure and at 14 months of age respectively. The behavioral test battery included tests of locomotor activity, tap startle, social behavior, anxiety, predator avoidance and learning. Long-term effects on neurochemical indices of cholinergic function were also assessed. Two weeks of DDT exposure had only slight effects on locomotor activity, while a longer five-week exposure led to hypoactivity and increased anxiety-like diving responses and predator avoidance at 1-week post-exposure. When te...

Source: Neurotoxicology and Teratology - January 5, 2020 Category: Toxicology Source Type: research